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Stellar classification
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Light from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with absorption lines. Each line indicates an ion of a certain chemical element, with the line strength indicating the abundance of that ion. The relative abundance of the different ions varies with the temperature of the photosphere. The spectral class of a star is a short code summarizing the ionization state, giving an objective measure of the photosphere's temperature and density.
Most stars are currently classified under the Morgan–Keenan (MKK) system using the letters O, B, A, F, G, K, M, L, T and Y, a sequence from the hottest (O type) to the coolest (Y type). The types R and N are carbon-based stars, and the type S is zirconium-monoxide-based stars. Each letter class is then subdivided using a numeric digit with 0 being hottest and 9 being coolest (e.g. A8, A9, F0, F1 form a sequence from hotter to cooler).
In the MKK system a luminosity class is added to the spectral class using Roman numerals. This is based on the width of certain absorption lines in the star's spectrum which vary with the density of the atmosphere and so distinguish giant stars from dwarfs. Luminosity class 0 stars for hypergiants, class I stars for supergiants, class II for bright giants, class III for regular giants, class IV for sub-giants, class V for main-sequence stars, class VI for sub-dwarfs, class VII for white dwarfs, and class VIII for brown dwarfs. The full spectral class for the Sun is then G2V, indicating a main-sequence star with a temperature around 5,800K.
Harvard spectral classification 1
- Spectrum images by Harvard spectral class 1.1
- Yerkes spectral classification 2
- Spectral peculiarities 3
- Conventional and apparent colors 4
History 5
- Secchi classes 5.1
- Draper system 5.2
- Harvard system 5.3
- Modern interpretation 5.4
Spectral types 6
- Class O 6.1
- Class B 6.2
- Class A 6.3
- Class F 6.4
- Class G 6.5
- Class K 6.6
- Class M 6.7
Extended spectral types 7
Hot blue emission star classes 7.1
- Class W: Wolf–Rayet 7.1.1
- The "Slash" stars 7.1.2
- The magnetic O stars 7.1.3
- The "class" OB 7.1.4
Cool red and brown dwarf classes 7.2
- Class L 7.2.1
- Class T: methane dwarfs 7.2.2
- Class Y 7.2.3
Carbon-related late giant star classes 7.3
- Class C: carbon stars 7.3.1
- Class S 7.3.2
- Classes MS and SC: intermediary carbon-related classes 7.3.3
- White dwarf classifications 7.4
- Non-stellar spectral types: Classes P and Q 7.5
- Degenerate and exotic stars 7.6
- Hot blue emission star classes 7.1
- Stellar classification, habitability, and the search for life 8
- Variable star classification 9
- Photometric classification 10
- See also 11
- Notes 12
- References 13
- External links 14
Harvard spectral classification
The Harvard classification system is a one-dimensional classification scheme using single letters of the alphabet, optionally with numeric subdivisions, to group stars according to their spectral characteristics. Main-sequence stars vary in surface temperature from approximately 2,000 to 50,000 K, whereas more-evolved stars can have temperatures above 100,000 K. Physically, the classes indicate the temperature of the star's atmosphere and are normally listed from hottest to coldest, as is done in the following table.
|Effective temperature[1][2][3]
|Conventional color description
|Actual apparent color[4][5][6]
(solar masses)
(solar radii)
Fraction of all
main-sequence stars[8]
|blue white
|deep blue white
|blue white
|yellow white
|yellowish white
|pale yellow orange
|Very weak
|light orange red
|Very weak
|red brown
|Extremely weak
|Extremely weak
|dark brown
|Extremely weak
- The conventional color description takes into account only the peak of the stellar spectrum. However, in actuality stars radiate in all parts of the spectrum, and because all spectral colors combined appear white, the actual apparent colors the human eye would observe are lighter than the conventional color descriptions. See Conventional and apparent colors.
- The mass, radius, and luminosity shown in the table for each class are appropriate only for stars on the main-sequence portion of their lives. The temperatures of giant and supergiant stars of the same spectral type are somewhat different, whereas the radius and luminosity can be dramatically different.
The spectral classes O through Y are subdivided by Arabic numerals (0–9), which can be further divided into half-subtypes. For example, A0 denotes the hottest stars in the A class and A9 denotes the coolest ones. The Sun is classified as G2. So far however, only Y dwarfs of subtypes 0–≈2 have been discovered.[11]
O, B, and A stars are sometimes called "early type", whereas K and M stars are said to be "late type″. This stems from an early 20th-century model of stellar evolution in which stars were powered by gravitational contraction via the Kelvin–Helmholtz mechanism whereby stars start their lives as very hot "early-type" stars, and then gradually cool down, evolving into "late-type″ stars. This mechanism provided ages of the Sun that were much smaller than what is observed, and was rendered obsolete by the discovery that stars are powered by nuclear fusion — these span spectral classes down to late L. However, brown dwarfs, whose energy comes from gravitational attraction alone, cool as they age and so progress to later spectral types. Brown dwarfs start their lives with M-type spectra and will cool through the L, T, and Y spectral classes; the faster the less massive they are — the highest-mass brown dwarfs can not have cooled to Y or even T dwarfs within the age of the universe . As this leads to a degeneracy between mass and age for given effective temperature and luminosity, no unique values can be assigned to a given spectral type.[7]
Spectrum images by Harvard spectral class
Yerkes spectral classification
The Yerkes spectral classification, also called the MKK system from the authors' initials, is a system of stellar spectral classification introduced in 1943 by
- Libraries of stellar spectra, D. Montes, UCM
- Spectral Types for Hipparcos Catalogue Entries
- Stellar Spectral Classification, Richard O. Gray and Christopher J. Corbally
- Spectral models of stars, P. Coelho
- Merrifield, Michael; Bauer, Amanda; Häußler, Boris (2010). "Star Classification". Sixty Symbols.
External links
- ^ a b c d Tables VII, VIII, Empirical bolometric corrections for the main-sequence, G. M. H. J. Habets and J. R. W. Heinze, Astronomy and Astrophysics Supplement Series 46 (November 1981), pp. 193–237, Bibcode: 1981A&AS...46..193H. Luminosities are derived from Mbol figures, using Mbol(☉)=4.75.
- ^ a b T. J. Dupuy & A. L. Kraus; Kraus (2013). "Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects". Science. published online 5 September 2013 (6153): 1492–1495.
- ^ Carsten Weidner; Jorick Vink (2010). "The masses, and the mass discrepancy of O-type stars". arXiv:1010.2204v1 [astro-ph.SR].
- ^ a b The Guinness book of astronomy facts & feats, Patrick Moore, 1992, 0-900424-76-1
- ^ "The Colour of Stars". Australia Telescope Outreach and Education. 2004-12-21. Retrieved 2007-09-26. — Explains the reason for the difference in color perception.
- ^ a b Charity, Mitchell. "What color are the stars?". Retrieved 2006-05-13.
- ^ a b c d Baraffe, Chabrier, Barman, Allard & Hauschildt; Chabrier; Barman; Allard; Hauschildt (2003). "Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458". Astronomy and Astrophysics 402 (2): 701.
- ^ a b c d e f g h LeDrew, G.; The Real Starry Sky, Journal of the Royal Astronomical Society of Canada, Vol. 95, No. 1 (whole No. 686, February 2001), pp. 32–33. Note: Table 2 has an error and so this article will use 824 as the assumed correct total of main-sequence stars
- ^ Dr. J. Davy Kirkpatrick and Dr. Robert Hurt, Infrared Processing and Analysis Center. "An Artist's View of Brown Dwarf Types".
- ^ Burrows et al. The theory of brown dwarfs and extrasolar giant planets. Reviews of Modern Physics 2001; 73: 719–65
- ^ J. D. Kirkpatrick et al. (2012). "Further Defining Spectral Type "Y″ and Exploring the Low-mass End of the Field Brown Dwarf Mass Function". The Astrophysical Journal 753 (2): 156.
- ^ Morgan, William Wilson; Keenan, Philip Childs; Kellman, Edith (1943), "An atlas of stellar spectra, with an outline of spectral classification", Chicago, Ill., The University of Chicago press
- ^ Philip C. Keenan, William Wilson Morgan; Keenan, P C (1973). "Spectral Classification".
- ^ SkyTonight: The Spectral Types of Stars
- ^ a b Pismis 24-1: The Stellar Upper Mass Limit Preserved, J. Maíz Apellániz et al. 2006
- ^ a b Spectroscopic study of the N159/N160 complex in the Large Magellanic Cloud, Cecilia Fariña et al. 2009
- ^ Early-type stars in the core of the young open cluster Westerlund2, G.Rauw et al. 2006
- ^ a b c d e f g Physical Properties of Wolf–Rayet Stars, Crowther, Paul A., 2007
- ^ Kaler, James B. (2011). Stars and Their Spectra: An Introduction to the Spectral Sequence (2nd ed.). Cambridge University Press. p. 88.
- ^ Sota, A.; Maíz Apellániz, J.; Walborn, N. R.; Alfaro, E. J.; Barbá, R. H.; Morrell, N. I.; Gamen, R. C.; Arias, J. I. (2011). "The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-Violet at R ∼ 2500". The Astrophysical Journal Supplement Series 193 (2): 24–50.
- ^ Andrew Hamilton. "What color is the sun?". Retrieved 2012-11-15.
- ^ Analyse spectrale de la lumière de quelques étoiles, et nouvelles observations sur les taches solaires, P. Secchi, Comptes Rendus des Séances de l'Académie des Sciences 63 (July–December 1866), pp. 364–368.
- ^ Nouvelles recherches sur l'analyse spectrale de la lumière des étoiles, P. Secchi, Comptes Rendus des Séances de l'Académie des Sciences 63 (July–December 1866), pp. 621–628.
- ^ pp. 60, 134, The Analysis of Starlight: One Hundred and Fifty Years of Astronomical Spectroscopy, J. B. Hearnshaw, Cambridge, UK: Cambridge University Press, 1986, ISBN 0-521-25548-1.
- ^ pp. 62–63, Hearnshaw 1986.
- ^ p. 60, Hearnshaw 1986.
- ^ Classification of Stellar Spectra: Some History
- ^ pp. 62–63, Stars and Their Spectra: An Introduction to the Spectral Sequence, James B. Kaler, Cambridge: Cambridge University Press, 1997, ISBN 0-521-58570-8.
- ^ p. 60–63, Hearnshaw 1986; pp. 623–625, Secchi 1866.
- ^ a b The Draper Catalogue of stellar spectra photographed with the 8-inch Bache telescope as a part of the Henry Draper memorial, Edward C. Pickering, Annals of Harvard College Observatory 27 (1890), Bibcode: 1890AnHar..27....1P. See in particular pp. 1–4.
- ^ a b pp. 106–108, Hearnshaw 1986.
- ^ pp. 111–112, Hearnshaw 1986.
- ^ Spectra of bright stars photographed with the 11-inch Draper Telescope as part of the Henry Draper Memorial, Antonia C. Maury and Edward C. Pickering, Annals of Harvard College Observatory 28, part 1 (1897), pp. 1–128, Bibcode: 1897AnHar..28....1M; see in particular Table I.
- ^ Spectra of bright southern stars photographed with the 13-inch Boyden telescope as part of the Henry Draper Memorial, Annie J. Cannon and Edward C. Pickering, Annals of Harvard College Observatory 28, part 2 (1901), pp. 129–263, Bibcode: 1901AnHar..28..129C; see in particular pp. 139–143.
- ^ pp. 117–119, Hearnshaw 1986.
- ^ Classification of 1,688 southern stars by means of their spectra, Annie Jump Cannon and Edward C. Pickering, Annals of Harvard College Observatory 56, #5 (1912), pp. 115–164, Bibcode: 1912AnHar..56..115C.
- ^ pp. 121–122, Hearnshaw 1986.
- ^ Relations Between the Spectra and Other Characteristics of the Stars, Henry Norris Russell, Popular Astronomy 22, no. 5, (May 1914), pp. 275–294, Bibcode: 1914PA.....22..275R, in particular p.277
- ^ Saha, M. N.; On a Physical Theory of Stellar Spectra, Proceedings of the Royal Society of London, Series A, Volume 99, Issue 697 (May 1921), pp. 135–153
- ^ Payne, C. H.; Stellar Atmospheres; A Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars, Ph. D. Thesis, Radcliffe College, 1925
- ^ An atlas of stellar spectra, with an outline of spectral classification, W. W. Morgan, P. C. Keenan and E. Kellman, Chicago: The University of Chicago Press, 1943.
- ^ Walborn, N. R. (1971). "Some Spectroscopic Characteristics of the OB Stars: An Investigation of the Space Distribution of Certain OB Stars and the Reference Frame of the Classification". The Astrophysical Journal Supplement Series 23: 257.
- ^ Revised MK Spectral Atlas for Stars Earlier than the Sun, W. W. Morgan, H. A. Abt, and J. W. Tapscott, Yerkes Observatory, University of Chicago and Kitt Peak National Observatory, 1978.
- ^ A New Spectral Classification System for the Earliest O Stars: Definition of Type O2, Nolan R. Walborn et al., The Astronomical Journal 123, #5 (May 2002), pp. 2754–2771, doi:10.1086/339831, Bibcode: 2002AJ....123.2754W.
- ^ "SIMBAD Object query : CCDM J02319+8915". Centre de Données astronomiques de Strasbourg. Retrieved 2010-06-10.
- ^ Checking the yellow evolutionary void. Three evolutionary critical Hypergiants: HD 33579, HR 8752 & IRC +10420
- ^ "On a cosmological timescale, The Earth's period of habitability is nearly over | International Space Fellowship". Spacefellowship.com. Retrieved 2012-05-22.
- ^ Optical Spectroscopy of 2MASS Color-Selected Ultracool Subdwarfs, Adam J. Burgasser et al., 2006
- ^ Astrometric and Spectroscopic Confirmation of a Brown Dwarf Companion to GSC 08047-00232, G. Chauvin et al., 2004
- ^ a b Stars as Cool as the Human Body
- ^ Figer, Donald F.; McLean, Ian S.; Najarro, Francisco (1997). "AK‐Band Spectral Atlas of Wolf‐Rayet Stars". The Astrophysical Journal 486: 420.
- ^ Bibcode: 1995A&A...295...75K
- ^ Tinkler, C. M.; Lamers, H. J. G. L. M. (2002). "Mass-loss rates of H-rich central stars of planetary nebulae as distance indicators?". Astronomy and Astrophysics 384 (3): 987.
- ^ Miszalski, B.; Crowther, P. A.; De Marco, O.; Köppen, J.; Moffat, A. F. J.; Acker, A.; Hillwig, T. C. (2012). "IC 4663: The first unambiguous \WN] Wolf-Rayet central star of a planetary nebula★". Monthly Notices of the Royal Astronomical Society 423: 934.
- ^ a b c Multiwavelength Systematics of OB Spectra, Walborn, N. R., 2008
- ^ Crowther, P. A.; Walborn, N. R. (2011). "Spectral classification of O2-3.5 If*/WN5-7 stars". Monthly Notices of the Royal Astronomical Society 416 (2): 1311.
- ^ Outstanding Issues in Our Understanding of L, T, and Y Dwarfs, J. D. Kirkpatrick, April 2007, arXiv:0704.1522. Accessed on line September 18, 2007.
- ^ a b Kirkpatrick, J. Davy; Reid, I. Neill; Liebert, James; Cutri, Roc M.; Nelson, Brant; Beichman, Charles A.; Dahn, Conard C.; Monet, David G.; Gizis, John E.; Skrutskie, Michael F. (July 10, 1999). "Dwarfs Cooler than M: the Definition of Spectral Type L Using Discovery from the 2-µ ALL-SKY Survey (2MASS)". The
- ^ a b Kirkpatrick, J. Davy (2005). "New Spectral Types L and T".
- ^ Kirkpatrick, J. Davy; Barman, Travis S.; Burgasser, Adam J.; McGovern, Mark R.; McLean, Ian S.; Tinney, Christopher G.; Lowrance, Patrick J. (2006). "Discovery of a Very Young Field L Dwarf, 2MASS J01415823−4633574". The Astrophysical Journal 639 (2): 1120.
- ^ Ultra-cool Diminutive Star Weighs In
- ^ LSR 1610-0040: The First Early-Type L Subdwarf, Lépine et al. 2003c
- ^ Discovery of the brightest T dwarf in the northern hemisphere, 2007
- ^ Discovery of the Y1 Dwarf WISE J064723.23-623235.5, J. Davy Kirkpatrick, Michael C. Cushing, Christopher R. Gelino, Charles A. Beichman, C. G. Tinney, Jacqueline K. Faherty, Adam Schneider, Gregory N. Mace, The Astrophysical Journal preprint (submitted 25 Aug 2013)
- ^ Y-Spectral class for Ultra-Cool Dwarfs, N.R.Deacon and N.C.Hambly, 2006
- ^ a b Wehner, Mike (2011-08-24). "NASA spots chilled-out stars cooler than the human body | Technology News Blog – Yahoo! News Canada". Ca.news.yahoo.com. Retrieved 2012-05-22.
- ^ a b NASA spots chilled-out stars cooler than the human body
- ^ NASA'S Wise Mission Discovers Coolest Class of Stars
- ^ The minimum Jeans mass, brown dwarf companion IMF, and predictions for detection of Y-type dwarfs, B. Zuckerman and I. Song, Astronomy and Astrophysics 493, #3 (January 2009), pp. 1149–1154, doi:10.1051/0004-6361:200810038, Bibcode: 2009A&A...493.1149Z.
- ^ a b c Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects, Trent J. Dupuy and Adam L. Kraus, Science Online (Sept 2013), doi:10.1126/science.1241917
- ^ a b c The Physical Properties of Four ~600 K T Dwarfs, S. K. Leggett et al., The Astrophysical Journal 695, #2 (April 2009), pp. 1517–1526, doi:10.1088/0004-637X/695/2/1517, Bibcode: 2009ApJ...695.1517L.
- ^ CFBDS J005910.90-011401.3: reaching the T-Y brown dwarf transition?, P. Delorme et al., Astronomy and Astrophysics 482, #3 (May 2008), pp. 961–971, doi:10.1051/0004-6361:20079317, Bibcode: 2008A&A...482..961D.
- ^ Exploring the substellar temperature regime down to ~550K, Ben Burningham et al., Monthly Notices of the Royal Astronomical Society 391, #1 (November 2008), pp. 320–333, doi:10.1111/j.1365-2966.2008.13885.x, Bibcode: 2008MNRAS.391..320B; see the abstract.
- ^ European Southern Observatory. "A Very Cool Pair of Brown Dwarfs", 23 March 2011
- ^ Bouigue, R. 1954, Annales d'Astrophysique, Vol. 17, p.104
- ^ Spectral Atlas of Carbon Stars (Barnbaum+ 1996)
- ^ Keenan, P. C. 1954 Astrophysical Journal, vol. 120, p.484
- ^ A Determination of the Local Density of White Dwarf Stars, J. B. Holberg, Terry D. Oswalt and E. M. Sion, The Astrophysical Journal 571, #1 (May 2002), pp. 512–518.
- ^ a b c d A proposed new white dwarf spectral classification system, E. M. Sion, J. L. Greenstein, J. D. Landstreet, J. Liebert, H. L. Shipman, and G. A. Wegner, The Astrophysical Journal 269, #1 (June 1, 1983), pp. 253–257.
- ^ C?rsico, A. H.; Althaus, L. G. (2004). "The rate of period change in pulsating DB-white dwarf stars". Astronomy and Astrophysics 428: 159.
- ^ A Catalog of Spectroscopically Identified White Dwarfs, George P. McCook and Edward M. Sion, The Astrophysical Journal Supplement Series 121, #1 (March 1999), pp. 1–130.
- ^ Physics of white dwarf stars, D. Koester and G. Chanmugam, Reports on Progress in Physics 53 (1990), pp. 837–915.
- ^ White dwarfs, Gilles Fontaine and François Wesemael, in Encyclopedia of Astronomy and Astrophysics, ed. Paul Murdin, Bristol and Philadelphia: Institute of Physics Publishing and London, New York and Tokyo: Nature Publishing Group, 2001. ISBN 0-333-75088-8.
- ^ a b Mapping the Instability Domains of GW Vir Stars in the Effective Temperature-Surface Gravity Diagram, Quirion, P.-O., Fontaine, G., Brassard, P., Astrophysical Journal Supplement Series 171 (2007), pp. 219–248.
- ^ §1, Detection of non-radial g-mode pulsations in the newly discovered PG 1159 star HE 1429–1209, T. Nagel and K. Werner, Astronomy and Astrophysics 426 (2004), pp. L45–L48.
- ^ The Extent and Cause of the Pre-White Dwarf Instability Strip, M. S. O'Brien, Astrophysical Journal 532, #2 (April 2000), pp. 1078–1088.
- ^ UV spectroscopy of the hybrid PG 1159-type central stars of the planetary nebulae NGC 7094 and Abell 43, Ziegler, M. et al. 2009
- ^ Digital Demo Room Stellar Structure and Evolution Simulator(date unknown)
- ^ a b "Stars and Habitable Planets". Solstation.com. Retrieved 2012-05-22.
- ^ a b c d e f g These proportions are fractions of stars brighter than absolute magnitude 16; lowering this limit will render earlier types even rarer, whereas generally adding only to the M class.
- ^ This rises to 78.6% if we include all stars. (See the above note.)
- Astrograph
- Guest star
- Spectral signature
- Stellar evolution
- Star count, survey of stars
- UBV photometric system
See also
Photometric systems with more colors and narrower passbands allow a star's class, and hence physical parameters, to be determined more precisely. The most accurate determination comes of course from spectral measurements, but there is not always enough time to get qualitative spectra with high signal-to-noise ratio.
Stars can also be classified using photometric data from any photometric system. For example, we can calibrate color index diagrams of U−B and B−V in the UBV system according to spectral and luminosity classes. Nevertheless, this calibration is not straightforward, because many effects are superimposed in such diagrams: interstellar reddening, color changes due to metallicity, and the blending of light from binary and multiple stars.
Photometric classification
Stars that exhibit change in luminosity are variable stars. There is a variable star classification scheme that encompasses existing stars that are classified in the spectra classification.
Variable star classification
For these reasons NASA's Kepler Mission has been searching for habitable planets mainly at main-sequence stars that are less massive than spectral type A but more massive than type M – namely dwarf stars of types F, G, and K, the most probable stars to host life.[89]
Working from these constraints and the problems of having an empirical sample set of only one, the range of stars that are predicted to be able to support life as we know it is limited by a few factors. Of the main-sequence star types, stars more massive than 1.5 times that of the Sun (spectral types O, B, and A) age too quickly for advanced life to develop (using Earth as a guideline). On the other extreme, dwarfs of less than half the mass of the Sun (spectral type M) are likely to tidally lock planets within their habitable zone, along with other problems (see Habitability of red dwarf systems).[89] Although there are many problems facing life on red dwarfs, due to their sheer numbers and longevity many astronomers continue to model these systems.
Stability, luminosity, and lifespan are all factors in stellar habitability. We only know of one star that hosts life, the Sun, a G-class star with an abundance of heavy elements and low variability in brightness. It is also unlike many stellar systems in that there is only one star in its system (see Planetary habitability, under the binary systems section).
Stellar classification, habitability, and the search for life
These objects are not stars but are stellar remnants. They are much dimmer and if placed on the HR diagram, would be placed further to the lower left-hand corner.[88]
Degenerate and exotic stars
Finally, the classes P and Q are occasionally used for certain non-stellar objects. Type P objects are planetary nebulae and type Q objects are novae.
Non-stellar spectral types: Classes P and Q
- DAV or ZZ Ceti: a hydrogen-rich pulsating white dwarf.[82], pp. 891, 895
- DBV or V777 Her: a helium-rich pulsating white dwarf.[83], p. 3525
- GW Vir, sometimes divided into DOV and PNNV: a hot helium-rich pulsating white dwarf (or pre-white dwarf.)[84], §1.1, 1.2;[85][86] These stars are generally PG 1159 stars, although some authors also include non-PG 1159 stars in this class.[84][87]
- DCV or Gliese 86 B: a cool helium-rich white dwarf.
Variable star designations:
- DAB: a hydrogen- and helium-rich white dwarf displaying neutral helium lines.
- DAO: a hydrogen- and helium-rich white dwarf displaying ionized helium lines.
- DAZ: a hydrogen-rich metallic white dwarf.
- DBZ: a helium-rich metallic white dwarf.
Extended white dwarf spectral types:[79]
Two or more of the type letters may be used to indicate a white dwarf which displays more than one of the spectral features above. Also, the letter V is used to indicate a variable white dwarf.[79]
The type is followed by a number giving the white dwarf's surface temperature. This number is a rounded form of 50400/Teff, where Teff is the effective surface temperature, measured in kelvins. Originally, this number was rounded to one of the digits 1 through 9, but more recently fractional values have started to be used, as well as values below 1 and above 9.[79][81]
- DA: a hydrogen-rich atmosphere or outer layer, indicated by strong Balmer hydrogen spectral lines.
- DB: a helium-rich atmosphere, indicated by neutral helium, He I, spectral lines.
- DO: a helium-rich atmosphere, indicated by ionized helium, He II, spectral lines.
- DQ: a carbon-rich atmosphere, indicated by atomic or molecular carbon lines.
- DZ: a metal-rich atmosphere, indicated by metal spectral lines (a merger of the obsolete white dwarf spectral types, DG, DK and DM).
- DC: no strong spectral lines indicating one of the above categories.
- DX: spectral lines are insufficiently clear to classify into one of the above categories.
The white dwarf types are as follows:[79][80]
- Examples: Sirius B (DA2), Procyon B (DA4), Van Maanen's star (DZ7)[78], Table 1
The class D (for Degenerate) is the modern classification used for white dwarfs – low-mass stars that are no longer undergoing nuclear fusion and have shrunk to planetary size, slowly cooling down. Class D is further divided into spectral types DA, DB, DC, DO, DQ, DX, and DZ. The letters are not related to the letters used in the classification of other stars, but instead indicate the composition of the white dwarf's visible outer layer or atmosphere.
White dwarf classifications
- Examples: R Serpentis, ST Monocerotis (MS)
- Examples: CY Cygni, BH Crucis (SC)
In between the M class and the S class, border cases are named MS stars. In a similar way border cases between the S class and the C-N class are named SC or CS. The sequence M → MS → S → SC → C-N is believed to be a sequence of increased carbon abundance with age for carbon stars in the asymptotic giant branch.
- Examples: S Ursae Majoris, BD Camelopardalis
Class S stars have zirconium monoxide lines in addition to (or, rarely, instead of) those of titanium monoxide, and are in between the class M stars and the carbon stars.[77] S stars have excess amounts of zirconium and other elements produced by the s-process, and have their carbon and oxygen abundances closer to equal than is the case for M stars. The latter condition results in both carbon and oxygen being locked up almost entirely in carbon monoxide molecules. For stars cool enough for carbon monoxide to form that molecule tends to "eat up" all of whichever element is less abundant, resulting in "leftover oxygen" (which becomes available to form titanium oxide) in stars of normal composition, "leftover carbon" (which becomes available to form the diatomic carbon molecules) in carbon stars, and "leftover nothing" in the S stars. The relation between these stars and the ordinary M stars indicates a continuum of carbon abundance. Like carbon stars, nearly all known S stars are giants or supergiants.
Class S
C: Carbon stars, e.g. R CMi
- C-R: Formerly a class on its own representing the carbon star equivalent of late G to early K stars. Example: S Camelopardalis
- C-N: Formerly a class on its own representing the carbon star equivalent of late K to M stars. Example: R Leporis
- C-J: A subtype of cool C stars with a high content of 13C. Example: Y Canum Venaticorum
- C-H: Population II analogues of the C-R stars. Examples: V Ari, TT CVn[76]
- C-Hd: Hydrogen-Deficient Carbon Stars, similar to late G supergiants with CH and C2 bands added. Examples: HD 137613, R Coronae Borealis
Originally classified as R and N stars, these are also known as 'carbon stars'. These are red giants, near the end of their lives, in which there is an excess of carbon in the atmosphere. The old R and N classes ran parallel to the normal classification system from roughly mid G to late M. These have more recently been remapped into a unified carbon classifier C, with N0 starting at roughly C6. Another subset of cool carbon stars are the J-type stars, which are characterized by the strong presence of molecules of 13CN in addition to those of 12CN.[75] A few dwarf (that is, main-sequence) carbon stars are known, but the overwhelming majority of known carbon stars are giants or supergiants.
Class C: carbon stars
Carbon-related stars are stars whose spectra indicate production of carbon by helium triple-alpha fusion. With increased carbon abundance, and some parallel s-process heavy element production, the spectra of these stars become increasingly deviant from the usual late spectral classes G, K and M. The giants among those stars are presumed to produce this carbon themselves, but not too few of this class of stars are believed to be double stars whose odd atmosphere once was transferred from a former carbon star companion that is now a white dwarf.
The mass range for Y dwarfs is 9–25 Jupiter masses, but for young objects might reach below one Jupiter mass, which means that Y class objects straddle the 13 Jupiter mass deuterium-fusion limit that marks the division between brown dwarfs and planets.[70]
The brown dwarf with the latest assigned spectral type, WISE 1828+2650, is a >Y2 dwarf with an effective temperature originally estimated around 300 K, the temperature of the human body.[66][67][74] Parallax measurements have however since shown that its luminosity is inconsistent with it being colder than ~400 K; the likely coolest Y dwarf currently known is WD 0806−661B with approximately 350 K.[2]
- Example: WISE 0410+1502, class Y0
- Example: WISE 0350-5658, class Y1
- Example: WISE 1405+5534, class Y1
- Y: < 600 K, ultra-cool brown dwarfs
Brown dwarfs of spectral class Y are cooler than those of spectral class T and have qualitatively different spectra from them. A total of 17 objects have been placed in class Y as of August 2013.[64] Although such dwarfs have been modelled[65] and detected within forty light years by the Wide-field Infrared Survey Explorer (WISE)[50][66][67][68][69] there is no well-defined spectral sequence yet with prototypes. Nevertheless, several objects have been assigned spectral classes Y0, Y1, and Y2.[70] The spectra of these objects display absorption around 1.55 micrometers.[71] Delorme et al. has suggested that this feature is due to absorption from ammonia and that this should be taken as indicating the T–Y transition, making these objects of type Y0.[71][72] In fact, this ammonia-absorption feature is the main criterion that has been adopted to define this class.[70] However, this feature is difficult to distinguish from absorption by water and methane,[71] and other authors have stated that the assignment of class Y0 is premature.[73]
Class Y
Class T and L could be more common than all the other classes combined if recent research is accurate. Study of the number of proplyds (protoplanetary discs, clumps of gas in nebulae from which stars and planetary systems are formed) indicates that the number of stars in the galaxy should be several orders of magnitude higher than what we know about. It is theorized that these proplyds are in a race with each other. The first one to form will become a proto-star, which are very violent objects and will disrupt other proplyds in the vicinity, stripping them of their gas. The victim proplyds will then probably go on to become main-sequence stars or brown dwarfs of the L and T classes, which are quite invisible to us. Because brown dwarfs can live so long, these smaller bodies accumulate over time.
- Examples: SIMP 0136 (the brightest T dwarf discovered in northern hemisphere)[63]
- Examples: Epsilon Indi Ba & Epsilon Indi Bb
- Examples: CFBDS 1448 a T dwarf with an exoplanet orbiting it
- T: ~500–1,300 K, cooler brown dwarfs with methane in the spectrum
Class T dwarfs are cool brown dwarfs with surface temperatures between approximately 700 and 1,300 K. Their emission peaks in the infrared. Methane is prominent in their spectra.[58][59]
Class T: methane dwarfs
- Example: VW Hyi
Example: 2MASSW J0746425+2000321 binary[61]
- Component A is an L dwarf star
- Component B is an L brown dwarf
- Example: LSR 1610-0040 (subdwarf)[62]
- Example: V838 Monocerotis (supergiants)
- L: 1,300–2,400 K, dwarfs (some stellar, some substellar) with metal hydrides and alkali metals prominent in their spectra.
Class L dwarfs get their designation because they are cooler than M stars and L is the remaining letter alphabetically closest to M. L does not mean lithium dwarf; a large fraction of these stars do not have lithium in their spectra. Some of these objects have masses large enough to support hydrogen fusion, but some are of substellar mass and do not, so collectively these objects should be referred to as L dwarfs, not L stars. They are a very dark red in color and brightest in infrared. Their atmosphere is cool enough to allow metal hydrides and alkali metals to be prominent in their spectra.[58][59][60] Due to low gravities in giant stars, TiO- and VO-bearing condensates never form. Thus, larger L-type stars can never form in an isolated environment. It may be possible for these L-type supergiants to form through stellar collisions, however, an example of which is V838 Monocerotis.
Class L
The new spectral types L, T and Y were created to classify infrared spectra of cool stars. This includes both red dwarfs and brown dwarfs that are very faint in the visual spectrum.[57]
Cool red and brown dwarf classes
In lists of spectra, the "spectrum OB" may occur. This is in fact not a spectrum, but a marker which means that "the spectrum of this star is unknown, but it belongs to an OB association, so probably either a class O or class B star, or perhaps a fairly hot class A star."
The "class" OB
They are O stars with strong magnetic fields. Designation is Of?p[55]
The magnetic O stars
There is a secondary group found with this spectra, a cooler, "intermediate" group with designation of Ofpe/WN9.[55] These stars have also been referred to as WN10 or WN11, but that has become less popular with the realisation of the evolutionary difference to other Wolf–Rayet stars. Recent discoveries of even rarer stars have extended the range of slash stars as far as O2-3.5If*/WN5-7, which are even hotter than the original slash stars.[56]
- Example spectra: Of/WNL[55]
The slash stars are stars with O-type spectra and WN sequence in their spectra. The name slash comes from their spectra having a slash.
The "Slash" stars
- Example: R136a1 (WN5h)
- Example: Gamma2 Velorum A (WC8)
- Example: WR93B (WO3)
Wolf–Rayet examples:
Although the central stars of most planetary nebulae (CSPNe) show O-type spectra,[53] around 10% are hydrogen-deficient and show WR spectra.[54] These are low mass stars and to distinguish them from the massive Wolf Rayet stars, their spectra are enclosed in square brackets: e.g. [WC]. Most of these show [WC] spectra, some [WO], and very rarely [WN].
WN,[18] spectrum dominated by NitrogenIII-V and HeliumI-II lines
- WNE (WN2 to WN5 with some WN6), hotter or "early"
- WNL (WN7 to WN9 with some WN6), cooler or "late"
- Extended WN classes WN10 and WN11 sometimes used for the Ofpe/WN9 stars[18]
- h tag used (e.g. WN9h) for WR with hydrogen emission and ha (e.g. WN6ha) for both hydrogen emission and absorption
- WN/C, WN stars plus strong CarbonIV lines, intermediate between WN and WC stars[18]
WC,[18] spectrum with strong CarbonII-IV lines
- WCE (WC4 to WC6), hotter or "early"
- WCL (WC7 to WC9), cooler or "late"
- WO (WO1 to WO4), strong OxygenVI lines, extremely rare
WR spectra range is listed below:[51][52]
Class W or WR represents the Wolf–Rayet stars, notable for spectra lacking hydrogen lines. Instead their spectra are dominated by broad emission lines of highly ionised helium, nitrogen, carbon and sometimes oxygen. They are thought to mostly be dying supergiants with their hydrogen layers blown away by stellar winds, thereby directly exposing their hot helium shells. Class W is further divided into subclasses according to the relative strength of nitrogen and carbon emission lines in their spectra (and outer layers).[18]
Class W: Wolf–Rayet
Spectra of some very hot and bluish stars exhibit marked emission lines from carbon or nitrogen, or sometimes oxygen.
Hot blue emission star classes
A number of new spectral types have been taken into use from newly discovered types of stars.[50]
Extended spectral types
- Examples: NML Cygni, WOH G64, VY Canis Majoris (hypergiants),
- Examples: Betelgeuse, Antares, Mu Cephei, KY Cygni, VV Cephei A (supergiants), UY Scuti (supergiant or hypergiant)
- Examples: Rasalgethi, Beta Pegasi (giants)
- Examples: Proxima Centauri, Barnard's star, Gliese 581, AD Leonis (red dwarfs)
- Examples: LEHPM 2-59,[48] SSSPM J1930-4311 (subdwarf)
- Example: APMPM J0559-2903 (extreme subdwarf)
- Examples: Teide 1 (field brown dwarf), GSC 08047-00232 B[49] (companion brown dwarf)
Although most class M stars are red dwarfs, the class also hosts most giants and some supergiants such as VY Canis Majoris, Antares and Betelgeuse, as well as Mira variables. Furthermore, the late-M group holds hotter brown dwarfs that are above the L spectrum. This is usually in the range of M6.5 to M9.5. The spectrum of a class M star shows lines belonging to oxide molecules, TiO in particular, in the visible and all neutral metals, but absorption lines of hydrogen are usually absent. TiO bands can be strong in class M stars, usually dominating their visible spectrum by about M5. Vanadium monoxide bands become present by late M.
Class M stars are by far the most common. About 76% of the main-sequence stars in the Solar neighborhood are class M stars.[nb 1][nb 2][8] However, because main-sequence stars of spectral class M have such low luminosities, none are bright enough to be visible to see with the unaided eye. The brightest known M-class main-sequence star is M0V Lacaille 8760 at magnitude 6.6 (the fractionally brighter Groombridge 1618 was once considered to be class M0 but is now considered to be as K5) and it is extremely unlikely that any brighter examples will be found.
Class M
- Examples: Alpha Centauri B, Epsilon Eridani, Arcturus, Aldebaran, Algol B, RW Cephei
They have extremely weak hydrogen lines, if they are present at all, and mostly neutral metals (Mn I, Fe I, Si I). By late K, molecular bands of titanium oxide become present. There is a suggestion that K Spectrum stars may potentially increase the chances of life developing on orbiting planets that are within the habitable zone.[47]
Class K stars are orangish stars that are slightly cooler than the Sun. They make up about 12%, nearly one in eight, of the main-sequence stars in the solar neighborhood.[nb 1][8] There are also giant K-type stars, which range from hypergiants like RW Cephei, to giants and supergiants, such as Arcturus, whereas orange dwarfs, like Alpha Centauri B, are main-sequence stars.
- "K STAR" redirects here. For the Korean nuclear fusion project, see KSTAR.
Class K
- Examples: The Sun, Alpha Centauri A, Capella, Tau Ceti, Kepler-22
Most notable are the H and K lines of Ca II, which are most prominent at G2. They have even weaker hydrogen lines than F, but along with the ionized metals, they have neutral metals. There is a prominent spike in the G band of CH molecules. G is host to the "Yellow Evolutionary Void".[46] Supergiant stars often swing between O or B (blue) and K or M (red). While they do this, they do not stay for long in the yellow supergiant G classification as this is an extremely unstable place for a supergiant to be.
Class G stars are probably the best known, if only for the reason that the Sun is of this class. They make up about 7.5%, nearly one in thirteen, of the main-sequence stars in the solar neighborhood.[nb 1][8]
Class G
Class F stars have strengthening H and K lines of Ca II. Neutral metals (Fe I, Cr I) beginning to gain on ionized metal lines by late F. Their spectra are characterized by the weaker hydrogen lines and ionized metals. Their color is white. About 1 in 33 (3.03%) of the main-sequence stars in the solar neighborhood are class F stars.[nb 1][8]
Class F
Ca II) at a maximum at A5. The presence of Si II, Mg II, Fe stars are among the more common naked eye stars, and are white or bluish-white. They have strong hydrogen lines, at a maximum by A0, and also lines of ionized metals (AClass
Class A
- Examples:
These stars tend to be found in their originating OB associations, which are associated with giant molecular clouds. The Orion OB1 association occupies a large portion of a spiral arm of the Milky Way and contains many of the brighter stars of the constellation Orion. About 1 in 800 (0.125%) of the main-sequence stars in the solar neighborhood are class B stars.[nb 1][8]
Class B stars are very luminous and blue. Their spectra have neutral helium, which are most prominent at the B2 subclass, and moderate hydrogen lines. Ionized metal lines include Mg II and Si II. As O and B stars are so powerful, they only live for a relatively short time. Thus, due to the low probability of kinematic interaction during their lifetime, they do not, and are unable to, stray far from the area in which they were formed.
Class B
- Alpha Camelopardalis
- Tau Canis Majoris
- Lambda Cephei
- Delta Circini A
- Plaskett's star
- Zeta Ophiuchi
- Delta Orionis
- Theta¹ Orionis C
- Sigma Orionis A
- Xi Persei
- Zeta Puppis
- Pismis 24-1
- Pistol Star
- Alnitak
- Mintaka
- Examples:
When the MKK classification scheme was first described in 1943, the only subtypes of class O used were O5 to O9.5.[41] The MKK scheme was extended to O9.7 in 1971[42] and O4 in 1978,[43] and new classification schemes have subsequently been introduced which add types O2, O3 and O3.5.[44]
O stars have dominant lines of absorption and sometimes emission for He II lines, prominent ionized (Si IV, O III, N III, and C III) and neutral helium lines, strengthening from O5 to O9, and prominent hydrogen Balmer lines, although not as strong as in later types. Because they are so massive, class O stars have very hot cores and burn through their hydrogen fuel very quickly, so they are the first stars to leave the main sequence.
Class O stars are very hot and extremely luminous, with most of their radiated output in the ultraviolet range. These are the rarest of all main-sequence stars. About 1 in 3,000,000 (0.00003%) of the main-sequence stars in the solar neighborhood are class O stars.[nb 1][8] Some of the most massive stars lie within this spectral class. Class O stars frequently have complicated surroundings which make measurement of their spectra difficult.
Class O
The following illustration represents star classes with the colors very close to those actually perceived by the human eye. The relative sizes are for main-sequence (or "dwarf") stars.
Spectral types
The fact that the Harvard classification of a star indicated its surface or photospheric temperature (or more precisely, its effective temperature) was not fully understood until after its development, though by the time the first Hertzsprung–Russell diagram was formulated (by 1914), this was generally suspected to be true.[38] In the 1920s, the Indian physicist Meghnad Saha derived a theory of ionization by extending well-known ideas in physical chemistry pertaining to the dissociation of molecules to the ionization of atoms. First he applied it to the solar chromosphere, then to stellar spectra.[39] The Harvard astronomer Cecilia Helena Payne (later to become Cecilia Payne-Gaposchkin) then demonstrated that the OBAFGKM spectral sequence is actually a sequence in temperature.[40] Because the classification sequence predates our understanding that it is a temperature sequence, the placement of a spectrum into a given subtype, such as B3 or A7, depends upon (largely subjective) estimates of the strengths of absorption features in stellar spectra. As a result, these subtypes are not evenly divided into any sort of mathematically representable intervals.
Modern interpretation
Useful mnemonics for remembering the spectral type letters are "Oh, Be A Fine Guy/Girl, Kiss Me" or "Oh Boy, An F Grade Kills Me". To also include the colder spectral classes L, T and Y, the first mnemonic can be extended by adding "Love To You."
In 1901, Annie Jump Cannon returned to the lettered types, but dropped all letters except O, B, A, F, G, K, and M, used in that order, as well as P for planetary nebulae and Q for some peculiar spectra. She also used types such as B5A for stars halfway between types B and A, F2G for stars one-fifth of the way from F to G, and so forth.[34][35] Finally, by 1912, Cannon had changed the types B, A, B5A, F2G, etc. to B0, A0, B5, F2, etc.[36][37] This is essentially the modern form of the Harvard classification system.
In 1897, another worker at Harvard, Antonia Maury, placed the Orion subtype of Secchi class I ahead of the remainder of Secchi class I, thus placing the modern type B ahead of the modern type A. She was the first to do so, although she did not use lettered spectral types, but rather a series of twenty-two types numbered from I to XXII.[32][33]
Harvard system
In the 1880s, the astronomer Edward C. Pickering began to make a survey of stellar spectra at the Harvard College Observatory, using the objective-prism method. A first result of this work was the Draper Catalogue of Stellar Spectra, published in 1890. Williamina Fleming classified most of the spectra in this catalogue. It used a scheme in which the previously used Secchi classes (I to IV) were divided into more specific classes, given letters from A to N. Also, the letters O, P and Q were used, O for stars whose spectra consisted mainly of bright lines, P for planetary nebulae, and Q for stars not fitting into any other class.[30][31]
|Hydrogen lines dominant.
|Did not appear in the catalogue.
|Wolf–Rayet spectra with bright lines.
|Planetary nebulae.
|Other spectra.
Draper system
In the late 1890s, this classification began to be superseded by the Harvard classification, which is discussed in the remainder of this article.[27][28][29]
- Class V: emission-line stars, such as γ Cassiopeiae and Sheliak.
In 1877, he added a fifth class:[26]
- Class IV: red stars with significant carbon bands and lines (carbon stars.)
In 1868, he discovered carbon stars, which he put into a distinct group:[25]
- Class I: white and blue stars with broad heavy hydrogen lines, such as Vega and Altair. This includes the modern class A and early class F.
- Class II: yellow stars—hydrogen less strong, but evident metallic lines, such as the Sun, Arcturus, and Capella. This includes the modern classes G and K as well as late class F.
- Class III: orange to red stars with complex band spectra, such as Betelgeuse and Antares. This corresponds to the modern class M.
During the 1860s and 1870s, pioneering stellar spectroscopist Father Angelo Secchi created the Secchi classes in order to classify observed spectra. By 1866, he had developed three classes of stellar spectra:[22][23][24]
Secchi classes
The reason for the odd arrangement of letters in the Harvard classification is historical, having evolved from the earlier Secchi classes and been progressively modified as understanding improved.
There are a few apparently green stars, but this is an optical illusion caused by the star being close to a bright red star.
The Sun itself is white and approximates a black body of 5780 K (see color temperature). It is sometimes called a yellow star, spectroscopically relative to Vega, may appear yellow or red when viewed through the atmosphere, or appear white if viewed when too bright for the eye to see any color. This is a natural consequence of the evolution of human optical senses: the response curve that maximizes the overall efficiency against solar illumination will by definition perceive the Sun as white although there is some subjective variation between observers. The D65 standard closely mimics the spectrum of the Sun although it is intended to represent a 6500K blackbody light source. The color of the Sun is subtly different from D65 and is a faint peachy shade relative to it.[21]
|Y CVn C5
|Betelgeuse M2Ia
|Cool red dwarf M5V
Conventional and apparent colors
For example, Epsilon Ursae Majoris is listed as spectral type A0pCr, indicating general classification A0 with strong emission lines of the element chromium. There are several common classes of chemically peculiar stars, where the spectral lines of a number of elements appear abnormally strong.
|Spectral peculiarities for stars
|Blending and/or uncertain spectral value
|Undescribed spectral peculiarities exist
|Special peculiarity
|Composite spectrum
|Emission lines present
|"Forbidden" emission lines present
|"Reversed" center of emission lines weaker than edges
|Emission lines with peculiarity
|Emission lines with P Cygni profile
|Spectral emission that exhibits variability
|N III and He II emission (for element name followed by Roman numeral see spectral line)
|NIV λ4058Å is stronger than the NIII λ4634Å, λ4640Å, & λ4642Å lines[15]
|SiIV λ4089Å & λ4116Å are emission in addition to the NIII line[15]
|N III emission, absence or weak absorption of He II
|Displays strong HeII absorption accompanied by weak NIII emissions[17]
|WR stars with emission lines due to hydrogen.[18]
|WR stars with hydrogen emissions seen on both absorption and emission.[18]
|He wk
|Weak He lines
|Spectra with interstellar absorption features
|Enhanced metal features
|Broad ("nebulous") absorption due to spinning
|Very broad absorption features due to spinning very fast[19]
|A nebula's spectrum mixed in
|Unspecified peculiarity, peculiar star.
|Peculiar spectrum, similar to the spectra of novae
|Red & blue shifts line present
|Narrowly "sharp" absorption lines
|Very narrow lines
|Shell star features
|Variable spectral feature (also "var")
|Weak lines (also "wl" & "wk")
|Abnormal CNO features[20]
|C absorption enhanced, N deficient
|N absorption enhanced, C and O deficient
|If spectrum shows enhanced metal features
|Abnormally strong Barium
|Abnormally strong Calcium
|Abnormally strong Chromium
|Abnormally strong Europium
|Abnormally strong Helium
|Abnormally strong Mercury
|Abnormally strong Manganese
|Abnormally strong Silicon
|Abnormally strong Strontium
|Technetium is present
|Spectral peculiarities for white dwarfs
|Magnetic white dwarf with detectable polarization
|Emission lines present
|Magnetic white dwarf without detectable polarization
|Spectral peculiarities exist
Additional nomenclature, in the form of lower-case letters, can follow the spectral type to indicate peculiar features of the spectrum.[14]
Spectral peculiarities
|Marginal symbols
|The star is between supergiant and bright giant.
|O9.5 Ia+
|The star is a hypergiant star.
|The star is either a subgiant or a dwarf star.
Marginal cases are allowed; for instance a star classified as Ia-0 would be a very luminous supergiant, verging on hypergiant. Examples are below. The spectral type of the star is not a factor.
- 0, Ia-0, Ia+ hypergiants or extremely luminous supergiants (later addition)), Example: Eta Carinae (spectrum-peculiar)
- Ia (luminous supergiants), Example: Deneb (spectrum is A2 Ia)
- Iab (intermediate luminous supergiants), Example: Betelgeuse (spectrum is M2 Iab)
- Ib (less luminous supergiants), Example: Eta Leonis (spectrum is A0 Ib)
- II bright giants, Example: β Scuti (HD 173764) (spectrum is G5 II)
- III normal giants, Example: ρ Persei (spectrum is O7.5 III(n)((f)))
- IV subgiants, Example: ε Reticuli (spectrum is K1–2 IV)
- V main-sequence stars (dwarfs), Example: AD Leonis (spectrum M3.5e V)
- VI subdwarfs, Example: SSSPM J1930-4311 (spectrum sdM7)
- VII (uncommon) white dwarfs. White dwarfs are represented with a prescript wD or WD.
Denser stars with higher surface gravity exhibit greater pressure broadening of spectral lines. The gravity, and hence the pressure, on the surface of a giant star is much lower than for a dwarf star because the radius of the giant is much greater than a dwarf of similar mass. Therefore differences in the spectrum can be interpreted as luminosity effects and a luminosity class can be assigned purely from examination of the spectrum. A number of different luminosity classes are distinguished:


text:
I've been struggling with this assignment for some time, but I feel as though I've finally got a hold on it. Problem is, I got it to work ONCE, then changed one tiny thing and broke it.
Okay, so the assignment was to write a program that computes how much an investment would be worth in a few years. Lots of cin for the various values and a formula that was a little bit annoying to figure out. Simple stuff, so you're probably all giggling at how I screwed it up. Laugh it up, fuzzball.
So here's the formula:
amount = principal(1 + rate / n) (n [A power. Dunno how to raise it in the post])(t [power again])
principal is the amount invested
rate is the decimal percentage rate
n is the number of times to compound per year
t is time in years
This is in math-speak, not attempted code. I'm not that dumb yet. So here's the sample run on the assignment paper:
Principal: 5000
Rate as a %: 6
Number of years: 10
Number of times to compound: 4
If $5000 had been invested for 10 years at 6%, the investment would now be worth $9070.09.
I feel the need to say this again: I got this to work. I put all the values in my code before trying the cin version, and it got it right.
Not so anymore. So here's the code I've got:
Code://Program to compute the value of and investment #include <iostream> #include <cmath> using namespace std; void main() { double principal, amount, rate, n, t, percent; cout << "Enter: " << endl; cout << "Principal: "; cin >> principal; cout << "Rate as a %: "; cin >> percent; rate = percent / 100.0; cout << "Number of years: "; cin >> t; cout << "Number to compound: "; cin >> n; amount = principal * pow(1 + rate / n, (n * t)); cout << "If " << principal << " had been invested for " << t << " years at " << rate << " %, the investment /n would now be worth " << amount << "." << endl; }

subset: commoncrawl


text:
Working on a game in the Corona SDK with Lua and I need help so the player animates on the line drawn. Right now he animates at the beggining and the end but not on the line.
Here is the player code:
function spawnPlayerObject(xPlayerSpawn,yPlayerSpawn,richTurn) --spawns Rich where we need him.
-- riches sprite sheet and all his inital spirites. We need to adjust this so that animations 3-6 are the only ones that animate when moving horizontally
local richPlayer = sprite.newSpriteSet(richSheet1,1,6)
sprite.add(richPlayer, "rich", 1,6,500,1)
rich = sprite.newSprite(richPlayer)
rich.x = xPlayerSpawn
rich.y = yPlayerSpawn
rich:scale(_W*0.0009, _W*0.0009) -- scale is used to adjust the size of the object.
richDir = richTurn
rich.rotation = richDir
physics.addBody( rich, "static", { friction=1, radius = 15 } ) -- needs a better physics body for collision detection.
And here is the code for the line:
function movePlayerOnLine(event)
--for the original image replace all rich with player.
if posCount ~= linePart then
richDir = math.atan2(ractgangle_hit[posCount].y-rich.y,ractgangle_hit[posCount].x-rich.x)*180/math.pi
playerSpeed = 5
rich.x = rich.x + math.cos(richDir*math.pi/180)*playerSpeed
rich.y = rich.y + math.sin(richDir*math.pi/180)*playerSpeed
if rich.x < ractgangle_hit[posCount].x+playerSpeed*10 and rich.x > ractgangle_hit[posCount].x-playerSpeed*10 then
if rich.y < ractgangle_hit[posCount].y+playerSpeed*10 and rich.y > ractgangle_hit[posCount].y-playerSpeed*10 then
posCount = posCount + 1
I don't think anything has changed recently but I have been getting an error when testing of "attempt to upvalue "rich" a nil value" on the second line,
richDir = etc.


text:
14 Pro Capture Aio Driver Download
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text:
It's time for meto stop running.
I need to believewhat people tell me.
Let all my fans knowI love 'em
but a gay fishjust can't live
in the outside world forever.
Don't be sadfor me, guys--
I'm going home !
Uh - c'mon !
♪ I been so lonely, girlI've been so sad and down ♪
♪ I couldn't understandwhy haters joked around ♪
♪ I wanted to be freewith other creatures like me ♪
♪ And now I got my wish
♪ 'cause I know thatI'm a gay fish ♪
Gay fish, yo'
I'm a fish, yo'
♪ It's alright, girl
♪ Makin' love to othergay fish ♪
♪ All those lonely nightsat the grocery store ♪
♪ In the frozen fish aislefeelin' like a whore ♪
♪ 'Cause I wasn't bein' truey'know everyone said ♪
♪ That I have tomake a switch ♪
♪ Now I knowthat I'm a gay fish ♪
Gay fish, yo'
I'm a fish, yo'
♪ Now I'm whereI belong, girl ♪
I'm Going Home!
Fishsticks s13e05
Kanye West finally embraces his true nature, and finds love underwater.


text:
It looks like LG and Google are soon going to unveil a white Nexus 4. The folks over at Tinhte have managed to get their hands on a white Nexus 4.
Externally, there are no changes in the white Nexus 4, except for everything being white compared to the black variant that is available now. The crystal reflection as seen on the black Nexus 4 is also visible on the white Nexus 4 under the right angles and lighting conditions.
Like the Galaxy Nexus though, the front of the white Nexus 4 is absolutely black, making for a nice (or weird) contrast.
At the moment it is unconfirmed as to when Google and LG plan to release the white variant of the Nexus 4. Up until now, LG and Google had been struggling to meet the demand of the Nexus 4, and it was only yesterday that the handset went back in sale on the Play Store in the United States and Canada.
Head over to Tinhte for more pictures of the Nexus 4 in white.


text:
The Thai economy is forecast to grow by 3.8% in 2018, supported by public investments in infrastructure, rising household consumption and exports.
Political situation
Head of state: King Vajiralongkorn (Rama X), since December 2016
Head of government: Prime Minister General Prayuth Chan-ocha (since August 2014)
Government type: Constitutional monarchy. Currently a military interim government is in power.
Population: 69.1 million
Stability restored for the time being
The military junta, which has been ruling the country since 2014, is determined to remain in power for the time being. A referendum on a new constitution, designed to curb the powers of populist politicians and to preserve the military's major political influence, was held in August 2016 and approved by 61% of voters. The new constitution went into effect in April 2017, while general elections are expected to be held in late 2018. After King Bhumibol's death, his son Maha Vajiralongkorn succeeded him on the throne in December 2016.
Economic situation
Higher growth expected in 2018
Thailand's economy grew 3.7% in 2017, mainly due to robust export performance, increased tourist arrivals (tourism accounts for 45% of services output), public expenditure growth and higher private consumption. In 2018 a moderate acceleration in GDP growth to 3.8% is forecast. The economic expansion will again be supported by public investments in infrastructure and an export sector which is benefitting from robust growth in the neighbouring countries. While the military-controlled government has declared economic revival to be its top priority and pursues policies to boost consumption and investments, the remaining political uncertainty has curbed private sector investments. The Thai banking sector is healthy, as banks are well capitalised. Monetary policy by the central bank is expected to remain loose in order to support growth. The Thai baht is subject to a managed floating exchange rate regime, which reduces volatility risks.
Due to rising government spending and lower tax revenues both the fiscal deficit and government debt have increased since 2016. That said, government finances remain sustainable, as government debt remains below 50% of GDP. Public debt composition is quite favourable (only 6% is denominated in foreign currency), and public debt held by non-residents amounts to just about 15%. This insulates the government from external shocks. The country´s solid payment capacity and liquidity is underpinned by moderate foreign debt (in 2017: 30% of GDP and 39% of exports). International reserves are forecast to amount to about 10 months of import cover in 2017 and 2018.
A more subdued long-term outlook
While Thailand´s short-term economic outlook is positive, the long-term perspective is less so, due to decreasing international competition, high private debt levels and long-term political uncertainty. While stable for the time being, Thailand´s political future remains uncertain. The simmering conflict arising from the deep political, social and economic division between the old establishment (royal court, army, judiciary and urban upper class) in the south and the rural poor in the north has yet to be resolved, and is unlikely to disappear soon. High income inequality and poverty have increased social instability, which together with the current autocratic political trend increases the likelihood of renewed large scale protests - and the incentive for the military government to introduce costly populist transfer policies in order to appease the rural poor.


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What sort of diary should I like mine to be? Something loose-knit and yet not slovenly, so elastic that it will embrace anything, solemn, slight or beautiful, that comes into my mind. I should like it to resemble some deep old desk or capacious hold-all, in which one flings a mass of odds and ends without looking them through. I should like to come back, after a year or two, and find that the collection had sorted itself and refined itself and coalesced, as such deposits so mysteriously do, into a mould, transparent enough to reflect the light of our life, and yet steady, tranquil compounds with the aloofness of a work of art. The main requisite, I think, on reading my old volumes, is not to play the part of a censor, but to write as the mood comes or of anything whatever; since I was curious to find how I went for things put in haphazard, and found the significance to lie where I never saw it at the time.
V. Woolf


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Due to the damage to the Harbour Bridge, Expect delays in the Courier network. Same-day connections across Auckland cannot be relied upon while Harbour Bridge traffic is disrupted. Damage sustained to the Harbour Bridge and resulting reduction in traffic capacity has created ongoing traffic congestion that is affecting the majority of the Auckland motorway network. New Zealand Transport Agency (NZTA) has indicated that it could be some weeks before the situation is resolved.
Your search for 'R3PACK' returned 11 results.


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Welcome to the last day of CHA Armchair Attendee Week! I hope you've enjoyed our week this week - I had a lot of fun checking out all of the sneak peeks, pics and video from the CHA show floor, and sorting through all of that to find the key trends I shared earlier this week.
For today's post, I (Vivian) asked Write. Click. Scrapbook. team members to tell me what their top "must have" is from this set of CHA releases. The only parameter I set was that they had to choose a product from a manufacturer whose design team they are not on. Some team members had an easy time doing this and were able to instantly name a favorite. Others took some time to think it over. Some of us had a really hard time and listed more than one product since our top "must have" was, in fact, a tie amongst several "must haves." Some are still thinking about it. Some lines were pretty popular amongst the team, as you will see below.
Without further ado, here, in alphabetical order by team members' last names, are our "must have" products:
Francine Clouden: Studio Calico Abroad Thickers and Alpha Stickers
Paula Gilarde: Crate Paper Storyteller Collection (especially the chipboard)
Donna Januzzi: Simple Stories Documented Mix & Match 6" X 8" Album
Vivian Masket: Dear Lizzy Neapolitan Date Stamp and Echo Park This & That Charming Collection
Lisa Ottosson: Pink Paislee Prairie Hill Collection (12 x 12 papers)
Christa Paustenbaugh: Crate Paper Storyteller Collection and Dear Lizzy Neapolitan Collection
Diane Payne: American Crafts Amy Tangerine Sketchbook Collection, in particular, the Remarks Pigment Stickers (the set at the far right)
Katrina Simeck: Lily Bee Double Dutch Collection
Celeste Smith: Studio Calico Abroad Collection (the papers, in particular)
Amy Sorensen: Bella Blvd Sopisticates Collection High Five Alphas
Emily Spahn: Heidi Swapp Instaframes and Bella Blvd Designer Tape
Keshet Starr: October Afternoon 9 to 5 Collection and Studio Calico Take Note Collection
Erin Sweeney: Studio Calico Classic Calico Vol 2 (especially the chevron mask and the washi tape) and Take Note Collections and the Crate Paper Storyteller Collection
Feel free to share your "must haves" in the comments below - we want to know what's caught your eye, particularly if we've missed seeing it!
I hope you've enjoyed CHA Armchair Attendee Week here at Write. Click. Scrapbook. this week! I don't know about the rest of you, but I can't wait until some of this new product hits stores!


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Rossa points us to the Guardian article on "why Germany may well leave the EU 'cos her economy is not only contracting, she's subsidising the ClubMeds".
Now I'm highly suspicious of anything in the Grauniad by default, especially something that purports to quote statistics and the comments thread immediately dropped into a discussion of Marxism, as one would expect at a leftwing rag. However, the article made the points:
Total exports are equivalent to around 43% of Germany's GDP and the eurozone accounts for less than 37% of total exports, according to recently revised figures. That means that exports to the eurozone nominally account for roughly 15% of German GDP. This share will fall further. In reality, however, the contribution of the eurozone to the German economy is even smaller. The reason for this is simple: the eurozone countries do not pay for most imports from Germany; most of Germany's current account surplus is financed by the Bundesbank.
Between 1998 and 2011, German exports grew by over 115%. Export growth, however, did not translate into economic growth. According to Eurostat, during 1998-2011 Germany grew at an average annual rate of close to 1.4%, compared to around 1.5% for France, 1.8% for the Netherlands, 2.7% for Sweden, 2% for Britain, and average growth of 1.7 % for the EU as whole. Germany also lagged significantly behind the United States which achieved over 2%. Only Japan, Italy, Portugal and, according to some calculations, Denmark performed worse than Germany.
While German industry has enjoyed record export and profit growth, ordinary Germans have not had much economic joy over the past 13 years. As Charles Dumas of Lombard Street Research has demonstrated, real personal disposable income per capita rose by just over 7% from 1998 to 2011, compared to growth of 13% for Spain and around or over 18% for Britain, France and the US. German income growth lagged behind almost all OECD countries; only Italy and Japan performed worse. Germany today is a poorer country compared to many EU members than it was in 1998.
A great shock to me was that the above turned out to be reasonable accurate. Back in October, the Telegraph ran the same story:
Germany has supplied BMWs to southern Europe and they have given it IOUs in return. Will those IOUs ever be honoured? That is the problem with trying to grow through unbalanced trade. In the end, your trade partners need something to pay you with. Not that the German economy has been a stonking success during the euro's existence.
Its average growth rate has been only 1.4pc, below the UK's – and below Spain's and Ireland's. The explanation is clear. Whereas consumer spending has grown by about 30pc in America and the UK, in Germany it has grown by only 10pc. The reason is that over the last 13 years, German workers' average real incomes have fallen by 4pc.
So why wouldn't Germany leave? The answer is for political reasons. It's only through the backdoor mechanism of the EU project that Germany realizes its age old ambition, the ambition of the old dirty money in Bavaria to achieve what the Kaiser and Hitler couldn't. As this is Germany's aim and as the dirty money runs to trillions, then some loss as a result of the IOUs are hardly going to dissuade it. And Merkel is very much a creature of the Bertelsmanns and other families.
This snippet is Illuminating:
In any case, Bertelsmann can be sure that Mr. Obama will read its "little aide, its little white book" very carefully. For — as Ms. Heuser failed to disclose and as was not mentioned either in an op-ed on Obama that she published in the Washington Post in July — the Bertelsmann Corporation happens to be the president-elect's principal source of income. It was Bertelsmann, namely, that agreed to pay Obama a reported $1.9 million in advances for a three-book deal that the then-senator-elect signed with its fully owned American subsidiary, the Random House publishing group, in December 2004.
And another:
The "synergies" between Bertelsmann and various agencies of the German government are numerous and obvious: so much so that Bertelsmann has taken on the trappings of a veritable state within the state. Consider only that Bertelsmann's "10th International Forum" in 2006 was held at the German Ministry of Foreign Affairs. Participants included German Chancellor Angela Merkel, then French Foreign Minister Dominique de Villepin, and European Commission President José Manuel Barroso. [Pajamas]
Edward Spalton refers to Germany's "natural hinterland" and any view of German Foreign Policy shows it to be continually interested in extending its role, not diminishing it. Horst Teubert, Editor Informationen zur deutschen Aussenpolitik, goes into more detail in his "Germany's Bid for Great Power Status through the EU."
Edward Spalton makes reference to Germany's mindset which is always expansionary and inclusive, e.g. the Holy Roman Empire and nothing has occurred to change its stance. Bavaria is still the centre of Illuminism and many old families are there and in Italy. Finally, Lord Stoddart of Swindon opined:
"This is a plot by people who want to abolish nation states and create a United States of Europe," he said. "The whole thing is barmy. These people are determined to achieve their final objective. The only hope for Britain is to leave the EU and become an independent nation."
Current talk of an in/out referendum here is therefore of vital interest to the Bertelsmanns and if they hold the power over the US President as suggested above, then one would imagine the US urging the UK to stay in the EU.


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If you are thinking of a beauty salon with the Hot Rollers attached to the ladies heads, then you are way off the mark. It's big and bright with the brisk and fast Las Vegas casino strip as the game setting. Right now, the pretty Blonde Lady is waiting to make you her date, as she will pay 10,000 coins as the highest jackpot.
Hot Roller symbols
The Hot Roller takes the action right to the most lavish and coolest strip in the west side. Money making and visibly the brightest spot on the casino strip, meet the foxiest and beautiful Lady, who will lavish you with kisses for every winning payline. Throw in a couple of Red Dice and you can be on roll as the Roulette Wheel, Casino Chips and the playing cards together will bring in the Hot Roller wins. You might as well celebrate your wins with a chilled glass of martini.
Hot Roller is a 5 reel 25 payline game with a very Vegas themed layout. The slot game does away with all the neon lighting and eye piercing layout, and opts for a rather sober looking marble background to the reels. A craps table is where the action takes place as the rolling dice will make you either a winner or a pauper.
Wilds: The blonde Lady will blow kisses at you every time you make her as part of the winning payline. She will pay you double for all the wins as she distracts and replaces the other symbols.
Scatters: For a wild spin of the reels, you can play the two part spins feature. Surprisingly, NextGen lets you play up to 36 free games. You need to roll 3 of the scattered Red Dice on the reels. The numbers on both the dice are multiplied to give you the number of free spins. Roll the white dice and you can win up to 6x multiplier. So, start rolling the dice and make the hot wins rolls into your account. The feature can be re-triggered at the same initial conditions which caused the feature. The dice appear only on middle 2, 3 and 4 reels.
Gamble Feature: The entire Las Vegas theme will go waste if there is no gambling feature thrown in. So bet on the next card colour or the card suit, and check whether it will bring a double or quadruple for all your wins.
Min / max satsning per snurr (£ / $ / €): 0.01 – 2.0
Jackpots (£ / $ / €): 10 000 mynt (basspel)
Stänga tankar
Hot Roller will have you rolling in money as the free spins and multipliers keep regularly coming in. The graphics might put you off, but who cares as long as the cash gets added to your bankroll right.


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Nouri al-Maliki's War Crimes never end. Since January, he's been bombing residential areas in Falluja and killing and wounding civilians. National Iraqi News Agency reports Nouri's bombing of Falluja's resedential neighborhoods left 6 people dead and twenty injured.
That was not the only violence today. Mu Xuequan (Xinhua) counts 40 dead from violence today.
National Iraqi News Agency reports a Nasiriyah roadside bombing left six people injured, an Arsriah Village bombing killed 2 people and injured four more, a Najaf car bombing killed 13 people and left seventy injured, a Mishahda suicide car bomber took his own life and the lives of 2 police members with five more left injured, 1 person was shot dead in Falluja (three more wounded), the Ministry of the Interior announced that bombings in Babil, Dhi Qar and Najaf left 2 people dead and 21 injured (the Najaf bombing they're counting was a roadside bombing that injured 8, not the car bombing we already noted), 1 police member was shot dead in Baghdad, the Island and the Desert Operations Command announced they killed 7 suspects in Wady Soub, Joint Operations Command announced they killed 5 suspects, a Mosul battle left 1 Iraqi soldier dead and another injured, 1 person was shot dead in al-Khalis, 1 little girl was shot dead in an attack on her al-Wajeehiya home and her father was left injured, 1 person was shot dead just outside Baquba, 1 person was shot dead in Al-Muqdadiya (another injured), a Mousl roadside bombing killed 3 police members, a battle near Ramadi left 7 rebels dead (twenty-one more injured), a Yarmouk roadside bombing left 2 people dead, Ahmed Nabil (a member of Nineveh Governor Ethyl al-Nujaifi's protection service) was shot dead outside his al-Aarabi home, and 1 corpse was discovered in Baghdad ("signs of strangulation and stabbing by sharpen tool").
Over the weekend, the month of May concluded and the monthly death toll was noted. UNAMI issued the following:
Baghdad, 1 June 2014 – According to casualty figures released today by UNAMI, a total of at least 799 Iraqis were killed and another 1,409 were injured in acts of terrorism and violence in May*.
The number of civilians killed was 603 (including 144 civilian police), while the number of civilians injured was 1108 (including 218 civilian police). A further 196 members of the Iraqi Security Forces were killed, and 301 were injured (not including casualties from Anbar operation).
"I strongly deplore the sustained level of violence and terrorist acts that continues rocking the country. I urge the political leaders to work swiftly for the formation of an inclusive government within the constitutionally mandated time frame and focus on a substantive solution to the situation in Anbar", the Special Representative of the United Nations Secretary-General (SRSG), Mr. Mladenov said.
Anbar excluded, Baghdad was the worst affected Governorate with 932 civilian casualties (315 killed, 617 injured), followed by Ninewa (113 killed 248 injured), Salahuddin (94 killed 146 injured), Kirkuk (22 Killed, 60 injured), Diyala (38 killed 28 injured).
*CAVEATS: Data do not take into account casualties of the current IA operation in Anbar, for which we report at the bottom the figures received by our sources.
Operations in Anbar
According to information obtained by UNAMI from the Health Directorate in Anbar, the total civilian casualties in Anbar up to 30 May were 195 killed and 499 injured, with 95 killed and 222 injured in Ramadi and 100 killed and 277 injured in Fallujah.
Other counts were compiled as well. Margaret Griffis (Antiwar.com) notes, "Antiwar.com compiled 2,249 fatalities, of which 1,075 were civilian and security member deaths. Another 1,953 people were wounded, including 87 militants." Iraq Body Count notes 1027 civilians killed for the month. AFP's count is 900.
We're getting closer to the half-way mark for 2014. AFP's Prashant Rao Tweeted the following:
So far in 2014, at least 4,139 people have been killed, 6,081 wounded by violence in Iraq -
@AFP: http://u.afp.com/IraqCasualties
Today, the Economist offers, "Most Iraqis here appear to support the end of Saddam's regime, but criticise the American government and military officials for inadequate post-war planning that has left Baghdad and much of the country in chaos. In 2013 over 7,800 civilians were killed, surpassing the total of 6,787 in 2008, during the conflict. This year is looking just as deadly, although many Iraqis hope against the odds that the recent elections will bring progress and stability."
Thug and prime minister Nouri al-Maliki wants a third term. His office issued the following today:
His Excellency Prime Minister Nouri Al Maliki said in an interview with Al-Iraqiya TV which will be aired at a later time we now have 175 guaranteed votes, but we want more partners who agree with us in the program and principles to be adopted in the next government , and he called on all political blocs to adopt understanding and dialogue in order to form the government as soon as possible and move towards construction and development.
With regards to the adherence of some political blocks and some politicians to what they call red lines against this or that party , Mr. Prime Minister said: I recommend that everyone read the developments well , there has been so many developments during the past four years and none can holds the neck of the political process anymore .
On the goal of the conference, which the Prime Minister called for in Anbar , his Excellency said it is intended to isolate the terrorists and strengthen national unity in Anbar and address reconstruction efforts .
On the issue of exporting oil from the Kurdistan region and its consequent effects , the Prime Minister said, that this act is in violation of the Iraq's sovereignty and Iraq's constitution , it cannot be accepted under any conditions. He stressed that there is no such thing as cutting the salaries of the Kurdistan region, but this is a banner raised for mobilization and incitement.
Nouri may or may not have the votes his office states. He's prone to making claims that aren't true. All Iraq News notes, "The Ahrar bloc within the Sadr Trend and the Kurdistani Democratic Party announced rejecting the nomination of the Premier, Nouri al-Maliki, for the third term of the Prime Minister Post."
The KDP is the most popular political party in the Kurdistan Regional Government. KRG President Massoud Barzani is the head of the KDP. (Most popular assertion is based on the KDP coming in first in the KRG provincial elections and first in the April 30th parliamentary elections.) On the subject of the Kurds, Hiwa Barznjy (Niqash) explores where the Kurds stand on the issue of Iraq's next prime minister:
The two most popular political parties originating in the semi-autonomous region of Iraqi Kurdistan are the Patriotic Union of Kurdistan, or PUK, and the Kurdistan Democratic Party, or KDP. The KDP appears to have 25 seats in Baghdad while the PUK has 21 – the next largest Iraqi Kurdish party, the Change movement, has nine seats.
And the PUK and KDP feel differently about working with al-Maliki for another term. The KDP are presently totally committed to getting rid of him while the PUK isn't quite as sure about that. The PUK's ailing leader, Jalal Talabani, who has been in hospital in Germany for over a year, is actually the President of Iraq and it is well known that the PUK has a better relationship with al-Maliki than the KDP. The question of whether the PUK would cut a separate deal with al-Maliki to become part of his coalition government has already been mooted.
The other question is whether the KDP would drop out of the united Kurdish group to support Ammar al-Hakim, who they are allegedly closer to. Al-Hakim is the leader of one of the other major Shiite Muslim parties in Baghdad, the Ahrar bloc, which represents the interests of the Islamic Supreme Council of Iraq in politics.
Parliamentary elections were held April 30th. May is ending but there's no one named prime minister yet.
In 2010, Iraq set the record for the longest time between elections and the formation of a government. They've since been bested and Nouri may be hoping they can reclaim their title. It certainly seems like a possibility based upon the remarks of MP Abbas al-Bayati. All Iraq News reports the State of Law MP insists that "the next government" will be formed "before the end of 2014." Way to shoot for the stars. If the government was formed on December 30th, that would be eight months to form the government.
The April 30th elections were a farce. Nouri and the IHEC did not allow Falluja and Ramadi to vote. Nouri's forces showed up in Sunni dominant areas and kept the polls closed for half-a-day before allowing them to open. It was one stunt after another guaranteed to decrease turnout.
Reuters' Ned Parker Tweeted the day of those elections:
More than 200
#Iraqi journalists waiting to vote got kicked out of a polling center at 6 pm deadline by #Iraqi SWAT who said leave or else.
The Iraqi Kurdish are not the only ones to have made this kind of announcement. The Sadrist movement, led by cleric Muqtada al-Sadr and represented in Parliament by the Ahrar bloc, has also said they don't want to see their former ally, al-Maliki, given a third term as Prime Minister.
Another of al-Maliki's most important former allies, the Muwatin, or Citizen, coalition which represents the interests of the Islamic Supreme Council of Iraq, led by another cleric Ammar al-Hakim, has expressed similar sentiments.
Both of the latter are mostly composed of Shiite Muslims, the same sect as al-Maliki. Meanwhile al-Maliki's long time opponents – mostly Sunni Muslim blocs and parties as well as some secular blocs – have also said they won't contemplate a third term for al-Maliki.
Al-Maliki's bloc has won around 94 seats and it's highly likely this share will increase to over 100 – anything from 102 to 110, analysts suggest - as the big bloc attracts smaller parties to its ranks to try and form a coalition big enough to be allowed to form the next government.
Meanwhile all of those who oppose a third term for al-Maliki number more than enough to form a government – they have around 180 seats out of Iraq's 328 seat Parliament. And some have suggested, perhaps rather optimistically, that these groups could form a kind of grand coalition because they all have the same focus: keeping al-Maliki out. Such a coalition could be described as grand because it would cross most of Iraq's ethnic and sectarian boundaries, uniting all those who usually jostle for political power for their own sector of Iraqi society; it would herald a true post-sectarian age for Iraqi politics.
If the PUK has thrown in with Nouri, it will further sideline the PUK.
In the provincial elections, Gorran (Change) destroyed the PUK. Months later in the parliamentary elections, the PUK increased their turnout via Jalal Talabani.
December 2012, Iraqi President Jalal Talabani suffered a stroke. The incident took place late on December 17, 2012 following Jalal's argument with Iraq's prime minister and chief thug Nouri al-Maliki (see the December 18, 2012 snapshot). Jalal was admitted to Baghdad's Medical Center Hospital. Thursday, December 20, 2012, he was moved to Germany. He remains in Germany currently.
A video showing Jalal -- the first since he went to Germany -- was distributed ahead of the parliamentary elections and rallied the PUK (Jalal is the head of the PUK) bumping up their turnout.
That's a one time stunt.
Video of Jalal won't do a damn thing again.
Jalal in the flesh might.
But if the PUK is partnering with Nouri, they will be sidelined in the KRG and Gorran will be the second most popular party. Nouri has refused to implement Article 140 (which would determine Kirkuk's status) and he's refused to hand over to the KRG their slice of the 2014 federal budget. These are two big reasons he's disliked, they are not the only ones. With the KDP standing up, if Jalal's PUK cowers at the feet of Nouri, they will be revealed as spineless and craven. Gorran will easily replace them.
In the KRG, the longing for a Kurdish nation-state has never gone away. It's also become a more visible dream with KDP members and others floating that the KRG might break away from Iraq. If the PUK can't lead the vision, the Kurdish people have no need to support the PUK.
And with Jalal on a deathbed or a never recovery, the PUK will look even more out of touch.
Still on the issue of the elections, All Iraq News reports MP Nabeel Harbo states that his alliance (Speaker of Parliament Osama al-Nujaifi heads the Motahidoun Alliance) is considering suing Iraq's Independent High Electoral Commission over the refusal to investigate serious allegations of voter fraud:
Speaking to All
On the topic of the Kurds . . .
Pope Francis received Kurdistan Regional Government President Massoud Barzani on Friday.
Barzani's office issued the following:
Rome, Italy (KRP.org) – Kurdistan Region President Masoud Barzani met with Pope Francis at the Vatican on Friday.
At the outset of the meeting, Pope Francis said that he was aware of the situation of Kurds and of their tragedies in the past. He commended President Barzani and the people of Kurdistan for what they have achieved, particularly in offering the Kurdistan Region as a safe haven for Syrian refugees and for Christians fleeing violence in other parts of Iraq.
The Pope also praised President Barzani for KRG's policy of promoting tolerance and peaceful co-existence among different religious communities. He expressed his hope that the KRG would continue to enjoy peace and prosperity.
For his part, President Barzani talked about tolerance in Kurdistan as a long-standing tradition that has popular support. He said that peoples of different religions have made sacrifices together in the past and now live side by side in peace and freedom.
On the situation of refugees and Christians who have sought refuge in Kurdistan, President Barzani said that the KRG would continue to provide assistance to them as a humanitarian duty.
Rudaw notes Barzani also met with Italy's Foreign Minister Federica Mogherini and that "the Kurdish flag was displayed alongside the Iraqi flag" at both meetings. Barzani's Chief of Staff Fuad Hussein explains, "Putting the Kurdistan flag is a message for the people of Kurdistan that the outside world understands the status of the Kurdistan Region. It's the recognition of the identity of Kurdistan's people and the legal identity of the people of Kurdistan."
While Barazani leads on Kurdish hopes, Jalal's still in his sickbed -- for two years now. Or maybe he's dead like the rumors say. Regardless, Barzani is showing real leadership while Jalal remains out of the country. Gorran may emerge as one of the KRG's two dominant political parties less for what Gorran does and more because the PUK self-implodes.
Last week in the United States, the calls for the resignation of VA Secretary Eric Shinseki intensified. May 5th, the American Legion called for Shinseki's resignation when the latest VA scandal had emerged (two sets of lists were kept on medical appointments -- one a fantasy one presented as real showing that veterans were receiving medical appointments within 14 days, the other list, the real list, showing veterans waiting weeks and months). US Senators -- Democrats and Republicans -- began calling for Shinseki to resign. Jewish War Veterans of America joined the American Legion's call for Shinseki to resign in a statement which included:
Washington, DC – In response to the damaging and verified accusations of mismanagement at VA hospitals, and the failure of VA leadership to properly respond to these claims, the Jewish War Veterans of the USA (JWV) calls for the immediate resignation of VA Secretary General Eric Shinseki.
"These systemic breaches of basic medical and ethical conduct on the part of the various administrators of many VA hospitals are beyond the pale. A new broom must come in and sweep the trash out, clean house from top to bottom," said JWV National Commander Dr. Robert Pickard, COL (USA Retired). "I met with Shinseki in Feb. 2014 and voiced veterans' concerns regarding the bonuses being distributed to various VA administrators in light of these horrible allegations. He corrected me and said that they were not "bonuses" but rather they were 'performance awards.' A stink weed by any other name would smell as bad! We respect and honor Shinseki's past experience and leadership in the military, and we honor his service to our country, but now it is past time to move on and get the job done by a new leader."
"It is time, in fact, it is past time, to restructure the leadership at the Department of Veterans Affairs. It is also time, in fact, it is past time, for a criminal investigation at the Department of Veterans Affairs. Many veterans are now concerned about going to the VA. Trust is gone." said Bob Zweiman, JWV Coordinating Committee Chairman. "It is important that new leadership take over and straighten out, swiftly and decisively, the many, many failings at the VA. From huge furniture purchases, to conferences being held at excessive costs, to performance awards that were not justified, and worst of all, to the patient delays at a steadily increasing number of VA hospitals."
As the scope of the allegations widens, it has become clear that the current leadership at the VA is not equipped to handle these challenges and investigate these matters.
Removing Shinseki from office is one of the significant ways to demonstrate that our government is not only willing, but actually doing, the right thing for our veterans.
Friday, Shinseki resigned. Sunday, the editorial board of the Modesto Bee weighed in, noting, "Still, this is a stain on Obama's presidency. He has promoted his interest in veterans and again declared this week that he is the president who ends wars. Part of doing so responsibly is making sure that those who fought are taken care of when they return home. His administration has not done that. Shinseki's ouster should not end the attention the White House, Congress or the public pays to the needs of veterans. That truly would be a national disgrace." Susan Page (USA Today) reports:
Americans' confidence in the medical care provided for soldiers returning from Iraq and Afghanistan has plummeted to new lows in the wake of the VA scandal, a USA TODAY Poll finds. Most people see the problem as widespread and systemic.
Just one in five rate the job the government does in providing veterans with medical care as excellent or good, about half the percentage who said that in a Pew Research Center survey in 2011. Then, half rated the care as "only fair" or poor; now seven in 10 do.
Lastly, Senator Bernie Sanders is the Chair of the Senate Veterans Affairs Committee. His office issued the following yesterday:
BURLINGTON, Vt., June 1 – Senate Veterans' Affairs Committee Chairman Bernie Sanders (I-Vt.) today outlined a comprehensive legislative package to address "reprehensible" behavior by VA officials and to correct underlying problems in access to medical care.
"There must be a culture of honesty and accountability within the VA and people who have lied or manipulated data must be punished. But we also have to get to the root causes of the problems that have been exposed. The simple truth is that with 2 million more veterans coming into the system in recent years there are many facilities within the VA that do not have the doctors, nurses and other personnel that they need to provide quality care in a timely way."
Sanders said a Thursday hearing of the veterans committee will consider the Restoring Veterans' Trust Act of 2014. The measure then could be put on a fast track for consideration by the full Senate. It would give the VA authority to immediately remove senior executives based on poor job performance while preventing wholesale political firings. It would provide veterans who can't get timely appointments with VA doctors the option of going to community health centers, military hospitals or private doctors. It would authorize VA to lease 27 new health facilities in 18 states. It would authorize emergency funding to hire new doctors, nurses and other providers in order to address system-wide health care provider shortages and to take other steps necessary to ensure timely access to care. To address primary care doctor shortage for the long-term, the bill would authorize the National Health Service Corps to award scholarships to medical school students and to forgive college loans for doctors and nurses who go to work at the VA.
Altogether, the bill would provide education, retirement security and other benefits for millions of veterans and their families. Virtually all of the provisions already have been approved by the Senate committee, many of them by unanimous votes, during previous legislative markup sessions.
Sanders said the need for congressional action was underscored last Wednesday when the VA's independent Office of Inspector General found that officials had lied about wait times for appointments at the Phoenix VA and other medical facilities. A separate audit delivered to President Barack Obama on Friday disclosed attempts by VA employees at two-thirds of VA hospitals and clinics to cover up delays in providing patient care.
Other provisions in Sanders' legislative package would:
• Upgrade VA's antiquated scheduling systems.
• Require President Obama to establish a commission on VA health care access and recommend, within 90 days, actions to bolster capacity.
• Extend comprehensive services and benefits to the most severely injured pre-9/11 veterans; standardize the process for sending patients to community health centers, military hospitals or other health care providers; and extend from five to 10 years access to VA health care for all recently-separated veterans.
• Provide help for veterans who suffered significant spinal cord, reproductive and urinary tract injuries and who now want to have children.
• Bolster the VA's ongoing effort to eliminate shrinking but still unacceptable backlogs in processing claims for disability benefits.
• Make certain that all veterans get in-state tuition rates for college costs covered by the Post-9/11 GI Bill.
• Improve the delivery of care and benefits to veterans who experienced sexual trauma while in the military.
• Remove the VA from annual budget battles by adopting so-called "advance appropriations" to protect veterans in case of a government shutdown.
• Restore a 1 percent cut in retirement cost-of-living adjustments that Congress enacted for current military service members.
To read a summary of the complete bill, click here.
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The Big Bang Theory has become my top favorite series from the time it started. The Big Bang Theory starring a group of four friends, all of whom have unusual habits has been a hit with the student and the geek culture.
The humor is something that only geeks get and that makes them feel special and exclusive.
Well, if you are a Linux fan and you have not noticed, Sheldon Cooper, the self-proclaimed genius and truest nerd on The Big Bang Theory has been seen using Ubuntu.
See for yourself in this video.
(Via: Seilo @ Geeky Ogre)


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Work of Biology Students & Prof. Henning Schneider is Published
October 6, 2012
The collaborative work of Henning Schneider, professor of biology, and his students is spotlighted in two recent publications.
An article in the journal Gene, titled "Cloning and expression of a zebrafish 5-HT2C receptor gene," is the work of Dr. Schneider and Jesse Williams,Christine Heumann, Marissa Yochum, Kala Pattar, Grace Noppert, Vanessa Mock, and Eric Hawley -- all students of his at DePauw -- along with Luke Fritzky from William Paterson University.
Gene is an an international journal of functional and evolutionary genomics. Their work is available via this link.
Schneider and his students also collaborated on a chapter in a book, Zebrafish Protocols for Neurobehavioral Research. The chapter, "Zebrafish and Drug Development: A Behavioral Assay System for Probing Nicotine Function in Larval Zebrafish," is the work of Professor Schneider, Eric W. Klee, Karl J. Clark, Andrew M. Petzold, Vanessa L. Mock, Julia M. Abarr, Jennifer L. Behrens, Ryan E. Edelen, Bryan A. Edwards, Joshua S. Hobgood, Meghann E. Pogue, Nishant K. Singh, and Stephen C. Ekkerot. Learn more here.Back